Versioning is the act of assigning a label to a software package (whatever from a single file to a complex application). You surely are used the Maven version scheme, and maybe heard about Semantic Versioning . But anything that labels software units in order can be understood as versioning: Timestamps, Commit ID trees, or just numbers or strings.
One may question the need for versioning. If you only need the latest “state” for your product, you are right, you don’t need versioning at all. Sadly, you will be missing a lot of interesting capabilities: